• 한국세라믹학회지
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• 제30권3호
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• pp.175-180
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• 1993

Influence of Nd3+ substitution for Pb2+ on the dielectric properties and the PbO evaporation according to substituting Nd3+ for Pb2+ in Pb(Mg1/3Nb2/3)O3 system ceramics have been investigated. The dielectric constant at the curie temperature and evaporation of PbO were decreased with increase of Nd3+ amounts. The percentage of PbO evaporation was 2.5wt% in the PMN system substituted Nd3+ for Pb2+, while it was 3.7wt% in the PMN system.

• 한국세라믹학회지
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• 제30권8호
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• pp.671-677
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• 1993

Effects of PbTiO3 addition on dielectric properties and extent of PbO loss in Nd-doped Pb(Mg1/3Nb2/3)O3 system were investigated. As the proportion of dopping increased, the phase transition temperature shifted to low region, and the dielectric constant at room temperature decreased rapidly. But as the proportion of PbTiO3 increased, the phase transition temperature shifted to high retion, and the dielectric constant at room temperature increased. The substitution of Nd3+ for Pb2+ decreased the amount of PbO evaporation, therefore the sample sintered well in case of only 1 mole% adding excess PbO.

• 한국재료학회:학술대회논문집
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• 한국재료학회 1992년도 춘계학술발표회
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• pp.115-116
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• 1992

• 한국세라믹학회지
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• 제30권8호
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• pp.629-634
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• 1993

Dielectric and electrostrictive properties of 0.99Pb(Mg1/3Nb2/3)O3-0.01Pb(Mn2/3W1/3)O3 system using KCl-NaCl salts have been investigated as a function of the amount of excess MgO. For the specimens calcined at $700^{\circ}C$ for 1h and then sintered at 115$0^{\circ}C$ for 4h, the perovskite phase and the relative density were about 98% and 95%, respectively. With the addition of excess MgO up to 10mol%, the dielectric constant and the electrostrictive strain increased due to the increase of density and grain size, and these properties were degraded by the further addition of excess MgO. For the 10mol% excess MgO added specimen, the maximum electrostrictive strain, Xmax, and the electrostrictive coefficient, Q11, were 4.5$\times$10-4, 3.5$\times$10-2m4/C2, respectively. These results were correlated with the property of PMW and microstructure.

• 한국세라믹학회지
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• 제33권5호
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• pp.556-562
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• 1996

In order to understand the electrostrictive behavior of Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) solid solutions the dielectric constants the electric-field-induced strains and the pyroelectric coefficients of (1-x)PMN-xPT (x=0.1-0.4) were investigated in the temperature range -50~20$0^{\circ}C$. For x=0.1~0.35 where the phase transi-tion is diffusive the strain has a maxima at the temperature of maximum pyroelectric coefficient (depolrizing temperature) rather than the temperature of maximum dielectric constant. For x=0.4 where the phase transition is relatively sharp the strain decreases monotonically as the temperature increases. Relationships among the above experimental results are discussed.

• 공업화학
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• 제5권5호
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• pp.862-870
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• 1994

출발물질로 $Pb(NO_3)_2$, $Mg(NO_3)_2$, $NbCl_5$를 선정하여 이들을 수용액상으로 $Pb(Mg_{1/3}Nb_{2/3})O_3$조성에 맞도록 각 수용액을 정확히 취하여 $Pb(Mg_{1/3}Nb_{2/3})O_3$ 1M용액이 되도록 조제하였다. 이 혼합용액은 상온에서 $PbCl_2$를 형성하므로 $70^{\circ}C$로 가열하여 $PbCl_2$를 용해시킨 후, 침전제 oxine을 가하여 pH 8~10에서 공침물을 얻었다. 이 침전물을 여과, 건조의 공정을 거처 $700{\sim}1000^{\circ}C$로 5시간 하소하여 $Pb(Mg_{1/3}Nb_{2/3})O_3$을 합성하였으며 합성된 분말은 평균입경이 $0.3{{\mu}m}$ 정도이고 모양은 구형이었다. 그리고 합성된 분말을 $2000Kg/cm^2$의 압력으로 성형하고, $1100{\sim}1200^{\circ}C$로 소성하여 이론밀도의 97.4%인 소결체를 얻었고 이때의 유전율은 1kHz에서 17000이고 유전손실은 상온에서 0.02%이었다.

• 한국세라믹학회지
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• 제26권2호
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• pp.249-257
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• 1989

Dielectric properties and the stability of the perovskite phase in the Pb(Mg1/3Nb2/3)O3 system have been investigated as a function of amount of BaTiO3 and firing temperature. In the specimens fired at 120$0^{\circ}C$, the pyrochlore phase was eliminated by the addition of 10-15m/o BaTiO3 and also the dielectric constant increased. However, the dielectric constant decreased with further addition of BaTiO3 even though no pyrochlore phase was found to be present. The reducing tendency of the pyrochlore phase decreased with lowering the firing temperature in the system of Pb(Mg1/3Nb2/3)O3 with BaTiO3. Dielectric properties in PMN ceramics were affected by the character of the BaTiO3 rather than the pyrochlore phase.

• 한국세라믹학회:학술대회논문집
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• 한국세라믹학회 2000년도 춘계총회,특별강연,심포지움,연구발표회
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• pp.29.1-29.1
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• 2000

• E2M - 전기 전자와 첨단 소재
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• 제6권2호
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• pp.122-128
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• 1993

본 연구에서는 0.45Pb(Fe$_{1}$2/Nb$_{1}$2/)O$_{3}$- (0.55-xPb(Fe$_{2}$3/W$_{1}$3/)O$_{3}$ (x=0.20, 0.25, 0.30) 세라믹을 950~990[.deg.C]에서 2시간 유지시켜 일반소성법으로 제작하였다. 제작된 시편에 대해 적층 세라믹 캐패시터로의 응용가능성을 고찰하기 위해 조성비와 소결온도에 따른 구조적, 유전적 특성을 조사하였다. PMN의 첨가량이 증가할수록 결정립 크기는 감소하였으며 상전이 온도는 증가하였다. 소결밀도는 970[.deg.C]에서 소결된 0.45PFN-0.30PFW-0.25PMN 시편에서 7.86[g/cm$_{3}$]의 최대값을 나타내었다. 유전상수는 990[.deg.C]에서 소결된 0.45PFN-0.25PFW-0.30PMN 시편에서 20,751의 최대값을 나타내었으며 유전손실은 모든 조성에서 5[%]이상을 나타내었다.

• 한국세라믹학회지
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• 제22권2호
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• pp.17-24
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• 1985

In the composition of $Pb(Mg_{0.15} W_{0.15})Ti_{0.35}-Zr_{0.35}O_3$ the effect of particle size on PbO vaporization were measured, . The initial step of discontinuous vaporization of unreated PbO during the calcining process was depended on the particle size. All additives $La_2O_3Nb_2O_5$ and $Al_2O_3$ inhibited the grain growth of the composition $Pb(Mg_{0.15} W_{0.15})Ti_{0.35}-Zr_{0.35}O_3$ +2wt% excess PbO. The dielectric and piezoelectric properties of the composition $Pb(Mg_{0.15} W_{0.15})Ti_{0.35}-Zr_{0.35}O_3$ were improved by the addition of 2wt% excess PbO and proper additive. The electromechanical planar coupling factor of 0.65 and mechnical quality factor of 390 could be obtained by adding 5wt% $Nb_2O_5$ to the composition 2wt% excess PbO+$Pb(Mg_{0.15} W_{0.15})Ti_{0.35}-Zr_{0.35}O_3$.